Neonatal and adult copper-64 metabolism in the pig and the possible relationship between the ontogeny of copper metabolism and Wilson's disease.

The copper profiles of neonatal mammals differ from those of the adult; in man they are similar to those found in people with Wilson's disease (WD). WD patients handle an intravenous bolus of radioactive copper in a characteristic manner which aids diagnosis. In view of the similarity between neonatal mammals and WD patients, we have studied the fate of an intravenous bolus of 64Cu injected into neonatal and adult pigs. In adult pigs, plasma 64Cu activity fell for 10 h and then slowly increased over the next 14 h as newly synthesised caeruloplasmin was secreted. In the neonate a secondary rise in 64Cu activity was not observed. Gel filtration of the soluble supernatant revealed significant differences in the association of 64Cu with hepatic copper proteins. In adults 64Cu associated predominantly with superoxide dismutase whilst in the neonate the 64Cu associated with metallothionein and a protein of high molecular weight. This study indicates that 64Cu export from the neonatal pig liver is in many ways similar to that found in WD. Additionally, there are similarities in the profile of hepatic 64Cu-binding proteins.